Radio frequency energy may be used to treat certain cardiac abnormalities, such as fibrillation, by ablating cardiac tissue. Radio frequency energy is delivered by RF generators in two phases: (i) the “ramp up” phase in which a relatively high amount of power is delivered to an ablating electrode until a desired set temperature is sensed by a thermocouple or thermistor, and (ii) the “regulation” phase in which power is still being delivered but regulated at a lower level to maintain the desired set temperature. This target temperature is predetermined by the operator, and is generally 50° to 55° C. for ablation of cardiac tissue.
Most RF generators have software modules which run simultaneously on portable computers during RF energy delivery to log the ablation episode. Typically, the parameters logged are sensed impedance, power delivered, as well as tissue temperature sensed by either thermistors or thermocouples. This information is typically used for post-procedural review.
One objective in RF ablation of cardiac tissue is to create deep lesions in the cardiac tissue while avoiding coagulum formation. RF energy must be delivered efficiently into the tissue, and not delivered and lost into the blood medium. Previous methods and systems are not adequate to assure that RF energy is delivered efficiently to cardiac tissue during an ablation procedure.
In previous systems, a master control card with a master controller is typically used to control the operation of various system components. Since the control is centralized, the loss of controller card means the system becomes inoperable.